Biomacromolecules Notes (Ch 1)

Back to the Basics – Molecules
~ H, S, P, C, N, O – group of non-metal atoms bonded together
~ Molecules that have no overall charge are called NON-POLAR. Not attracted to water so therefore are known as HYDROPHOBIC.
~ Many molecules have regions of positive or negative charge, they are called POLAR. These are attracted to water and known as HYDROPHILIC
~ Molecules with complementary SHAPE and CHARGE will BIND together
~ The interactions that will occur between molecules will depend on the characteristics present (Right shape and right charge = BIND TOGETHER)

---

Biomacromolecules
~ Giant molecules that play an essential role in both the structure and function of cells.

Type of Biomacromolecule	Subunits/Monomers	Linkage / Bond	Cellular Function
Lipids	Fatty acids & Glycerol	Ester Linkages	Energy store, component of cell membrane, signalling molecules
Complex CHO’s Polysaccharides	Simple sugar monomers	Glycosidic Linkage	Energy store, structural components of cells
Nucleic acids Polynucleotides	Nucleotide monomers	Phosphodiester Linkage	Information molecules that constitute an organism’s genetic material
Proteins Polypeptides	Amino acid monomers	Peptide Linkage	Proteins have many diverse roles. They control & regulate cellular processes, assist in transport of substances, act as receptors and as structural components

Condensation Reaction
When 2 monomers join together to form a polymer a bond/ linkage is formed. A water molecule is released.
Hydrolysis Reaction
When a bond/linkage is spilt into 2 monomers. A water molecule is used (splits to form hydrogen and oxygen) and is put into each monomer.

---

LIPIDS

CLASS	EXAMPLE	FUNCTION
Fatty Acid	Stearic Acid, Oleic Acid	Energy Source, Subunits of other lipids
Triglycerides	Fats and Oils	Energy storage
Phospholipids	Phospholipids	Structural component of plasma membranes
Glycolipids	Glycolipids	Recognition sites on plasma membrane
Steroids	Cholesterol, Sex hormones	Component of plasma membrane, signalling molecules
Terpenes	Vitamin A	Antioxidant

---

CARBOHYDRATES

Simple Carbohydrates	Monosaccharides	Glucose	Fuel molecule
		Fructose	Fuel molecule
		Ribose	Component of the nucleotide for RNA
	Disaccharides	Sucrose	Transports sugar in vascular plants
		Lactose	Component of milk
		Maltose	Obtained in the b/down of starch
Complex Carbohydrates		Starch	Storage molecule in plants
		Glycogen	Storage molecule in animals
		Cellulose	Component of the plant cell wall
		Chitin	Component of the exoskeletons of insects and crustaceans

---

PROTEINS – 4 major classes based upon their function within the cells

Class	Function
Catalytic Proteins	E.g. Enzymes. Control & regulate chemical reactions in the cell
Structural Proteins	Provide support & shape the cell & are components of many structures
Mobility Proteins	Proteins are involved in movement of cells
Regulatory Proteins	Proteins regulate the movement of substances across the plasma membrane, act as signals between cells, are components of the immune response and can be toxins that assist in defence & food capture

~ Each protein molecule has a characteristic 3D shape that results from coiling and folding of the polypeptide chain
~ The function of the protein depends upon the shape of the molecule
~ A protein molecule has 3 or 4 levels of organisation:
1. Primary Structure: Simply the order or sequence of amino acids that have been assembled into a polypeptide chain (this has been genetically determined)

2. Secondary Structure: Hydrogen bonding between H and O or N atoms in the peptide bond fold or coil, the polypeptide to form alpha helices or beta sheets. This causes R groups to come closer together.

3. Tertiary Structure: As the R groups have come closer together, they attract + to –

4. Quarternary Structure: When more than 1 polypeptide chain come together and interact to form a protein.

---

NUCLEIC ACIDS

	Prokaryotic Cell	Eukaryotic Cell
DNA	Found on the Single Chromosome in the cytoplasm and as circular structures called Plasmids	Found on linear structures called chromosomes in the nucleus. Also found in mitochondria & Chloroplasts
RNA	mRNA in the cytoplasm tRNA in the cytoplasm rRNA as a compontent of ribosomes	mRNA in the nucleus & cytoplasm tRNA in the cytoplasm rRNA as a compontent of ribosomes